The Misconception of HDR Photography

You’ve seen the term on social media, on every photo posting websites.

I’m sure you’ve seen ‘HDR photo’. You’re probably mesmerized by the ‘HDR effect’ the first time you saw it, at least I did.

The ugly truth is…

This is probably what you and most people know it for:

The “HDR look”

My aim is to change your perception of HDR by the end of this tutorial.

So stay with me 🙂

It’s More Than Just Crazy Lights and Funky Colors

HDR stands for High Dynamic Range.

And dynamic range simply means the range of brightness and darkness present in a scene. It’s different in every scene.

For example…

The dynamic range during sunset is higher than the dynamic range during midday.

Sometimes, the dynamic range is so high that our camera can’t record the full range of brightness and darkness present at the same time.

So we use a technique called HDR photography to overcome this problem.

HDR Image Can Be Created In Two Ways

What most people know about HDR is:

You shoot multiple exposures, load them into a software and click ok for the magic to happen.

That’s creating with an HDR software, and this is what many of us known HDR for.

There’s another way of creating HDR image called digital blending or exposure blending – instead of merging the photos with a software, you do it manually.

You’re thinking:

Why would I do that?!

For the purpose of this tutorial, I’ll focus mainly on creating images with an HDR software.

HDR created with Photomatix Pro

What Is HDR?

HDR is a technique that allows a wide range of brightness and darkness to be included and balanced in a single image.

It extends the dynamic range of an image that wouldn’t normally be achievable with a single exposure.

Now here’s an interesting fact…

When we see something with very bright lights and very dark shadows, the pupils and the lens in our eyes change in size rapidly to control and focus the light entering our eyes.

That’s the reason we can see details in bright and dark areas at the same time.

And that’s how we’re different from how our camera “sees” a scene.

The Major Limitation of A Camera

The glasses insides a camera lens are rigid and cannot change in size to adapt the light entering from the front of the lens.

Here’s what happens:

When a lens lets more light in, the darker areas may be correctly exposed but the very bright areas will be overexposed.

When a lens restricts the amount of light in, the very bright areas will be correctly exposed but the darker areas will be underexposed.

This is exactly what happens when you point your camera directly at the sun.

Before we go any further, you should know the different between dynamic range and extended or high dynamic range.

Dynamic Range

Dynamic range is the range of brightness that can be seen or recorded by a medium.

And what’s a medium?

It’s a substance that transmits or carry on the information.

In photography, a medium can be the human eye, a printed photo or a photo displayed on a monitor.

And remember this…

Dynamic range is relative and different medium has a different dynamic range.

Extending The Dynamic Range

Remember we said how cameras sometimes cannot record the same amount of brightness we see?

When we create a high dynamic range image, we extend the dynamic range of the image by exposure fusion.

What does that mean?

We combine multiple images of different exposure into one single file. This compresses all the brightness and colors into one place.

By doing so, we’ve extended what a single exposure image normally can’t achieve.

We have created a high dynamic range image.

Dynamic range explained

3 Reasons To Create HDR

It’s to create what a camera couldn’t.

That’s not all…

There are other good reasons why we bother to spend time to create HDR:

It’s necessary. I’ve told you all about dynamic range and how our camera cannot capture the full dynamic range at times.

In the name of creativity. Express the creativity within! You can choose to create natural or surreal HDR effect. There is no right or wrong, get the HDR photo effects that you want!

Shadow de-noise. Even though some of your images looks well exposed, you can still get noise when you brighten up the shadows significantly. This is because of the higher noise-to-signal ratio in the photosites. By merging into HDR, you add new brightness and color information to the pixels in the shadows.

5 Steps To Create An HDR Image

Follow these step-by-step guide to a successful HDRI. 🙂

#Step 1: Tools

You probably already have most of these.

E.g. a camera?

A camera capable of manual control of the shutter speed and recording image in RAW

Tripod or a steady pair of hands

Remote release but it’s not absolutely essential

HDR software

#Step 2: Exposure Bracketing – Automatic

Use the automatic exposure bracketing (AEB).

Setting 3 bracketed exposure at 1EV

You can use this to bracket 3, 5, 7, or even more images.

Noticed how it’s always in odd numbers?

Bracketed images are always in pairs [-1EV, +1EV] or [-2EV, +2EV], and this is coupled with the base image [0EV].

What about EV?

EV stands for exposure value, also known as “stop”. One stop up doubles the value of the shutter speed (1/250 to 1/500) and one stop down halves it (1/250 to 1/125).

Now here’s what you do:

Go to the menu of your camera, look for “automatic exposure bracketing” or “AEB”.

Depending on your camera, you can set the number of bracketed exposure to 3 or 5 (I’m not sure if some cameras can go even higher).

You can also set the interval between each EV: 1 stop, 1/2 stop or 1/3 stop in most cameras.

Mount it on a tripod. If you’re shooting handheld, hold the camera still by supporting the bottom of the camera with one hand and holding on the side where the trigger is with the other.

Switch the camera mode to aperture priority (Av). Set the appropriate ISO (as low as possible or keep it at 100 if you have a tripod). Use matrix metering.

Frame the scene and take your shots.

To make your life easier, set the shooting mode to continuous. Press and hold the trigger to take all bracketed shots in one go.

#Step 2 (Alternative): Exposure Bracketing – Manual

You must be scratching your head on this and ask: Why would you do that?

Some photographers like to do it themselves.

That’s not all…

You’ll need to go manual if you want to bracket more than what your camera can do for you (e.g. 9 exposures).

You MUST use a tripod or stabilize the camera with a bean bag/put it on a hard surface.

Switch the camera mode to aperture priority (Av). Set the aperture you want, half press the trigger and take a note of the shutter speed.

Now switch the camera mode to manual. Set the shutter speed, aperture and ISO to the settings in Av mode earlier.

Frame the scene and take a shot.

Now either stop up or stop down the shutter speed. I recommend stopping up or down by “1 stop” to start with until you’re more confident in calculating the shutter speed. E.g., if the initial shutter speed is 1/500, 1 stop down would halve it to 1/250, and 1 stop up would double it to 1/1000.

Take all the “stop up’ images first, then go to “stop down”. You can do it the other way round if you like.

Check the histogram for each image and bracket as many exposures as you need!

#Step 3: Choose A Method To Create HDRI

Load multiple exposures or a single RAW for HDR in Photomatix Pro 5

You’ll still need an HDR software.

But you don’t always need multiple exposures depending on what kind of images you have.

Merging multiple exposures. You want to create a high dynamic range image for a high contrast scene.

Tone mapping a single image. Sometimes all you have is a single RAW file. Or maybe you want to use HDR software’s tonal adjustments can do for a dull image. Works best if you have a photo with mostly midtones.

Triple or double processing a single RAW image. This means duplicating your image an extra or 2 copies. Change the exposure of the copies to, say, -1EV and +1EV. Now you have the images in different exposures and you can merge into HDR using the first method.

Expert Tips

Switch on “mirror lockup” for the absolute sharpness of your images. When mirror lockup is on, press the trigger first to lock up the mirror and the second time to open the shutter curtain.

If you find the above tedious, switch to live view and press the trigger. The mirror locks up during live view so you only have to press the trigger once! (this only applies to DSLR user)

Shoot RAW. You’re going to need all the color information for tone mapping.

Below is the before and the after of a single RAW image tone mapped in Photomatix Pro 5. Not too shabby!

#Step 4: Software

This is where most beginners stuck.

Because of budget or don’t do HDR frequent enough to invest in a software.

Fusion

Comparison

Challenges In HDR

Here are some common issues that you may come across when processing your bracketed exposures.

Movement

People, moving vehicles, trees, water.

You name it.

Anything that moves or changes position while you’re bracketing exposure will create what we called “ghosting”.

Movement can be a big challenge in crowded places like in the image below.

Movement causes ghosting in HDR

This was taken inside the Pantheon in Rome. There is no way you can get a clean shot in a tourist hotspot like this.

So what can you do?

Software like Photomatix Pro or Adobe Lightroom has deghosting tool to clean up the mess.

What it does is replaces the ghosting with one of the bracketed exposures to get rid of the movement artifact.

Alternatively, layer masking in Photoshop:

Place a bracketed exposure on top of the image and add a black mask. Use a soft white brush to gradually paint over the mask, starting with a low opacity. Apply a few passes until you’re happy with the result. You can change the blend mode to make the masking more unnoticeable.

If this is too technical…

Then tone map a single RAW image or do double/triple processing.

Halo

Very common and you see it all the time especially in the ultra-surreal effect.

This happens as you increase the strength of the effect to darken the highlights and brighten the shadows.

I’ll give you an example:

The transition between indoor and outdoor like the image below. There’s a rim of light around the round window that’s supposed to be bright (because of the light coming in).

Halos

The solution is simple…

Reduce the strength. It’s a sign that you’ve applied too much to your image.

Alignment

Sometimes you get images that are not aligned very well.

And you wonder why…

This typically happens when you bracket your exposures handheld or your tripod moved.

Some HDR software like Photomatix Pro has a few options for you to align the images.

If the issue with alignment is significant, then you essentially have 2 options.

Pick and choose the ones that are more aligned to each other and try again.

Use single image tone mapping or double/triple processing.

And for secret option number 3, don’t merge into HDR photo. What’s the worst that can happen, right? 🙂

Noise and Grain

If your bracketed exposures have noise because of high ISO, then your image will inevitably inherit the problem in a more exaggerated way.